Cryptic antifungal compounds active by synergism with polyene antibiotics

Anti-Candida activity and biocompatibility of silver nanoparticles associated with denture glaze: a new approach to the management of denture stomatitis

The association of silver nanoparticles (AgNps) to sealant agent Palaseal® can be a promising alternative for complete denture wearers who may develop denture stomatitis (DS). The study aimed to evaluate the anti-Candida and biocompatible potential of silver nanoparticles synthesized by three routes associated with denture glaze to prevent and/or treat oral candidiasis. Surface acrylic resin specimens were treated with different associations of glaze with AgNps (VER+AgUV, VER+AgTurk and VER+AgGm). As controls, specimens were treated with glaze+nystatin (VER+Nyst), glaze only (VER) or submerged in PBS (PBS). Afterwards, Candida albicans biofilm was developed for 24 h, 15 d and 30 d. Subsequently, the biofilm was quantified by CFU/mL, XTT assay and confocal laser scanning microscopy. Fibroblasts were submitted to conditioned medium with the same associations for 24, 48 and 72 h and LIVE/DEAD® viability test was carried out. Regardless of the period, there was a significant reduction (p < 0.01) of viable fungal cells load, as well as inhibition of fungal metabolic activity, in specimens treated with glaze+AgNps associations, compared to VER and PBS. The anti-Candida effects of the associations were similar to the VER+Nyst group, with emphasis on VER+AgGm, which showed the highest percentage values of non-viable fungal cells maintained over time. The associations did not prove toxicity to fibroblasts. The AgNps exerted antimicrobial activity against C. albicans biofilms and are biocompatible. The most effective results were achieved with the association of glaze+silver nanoparticles synthesized by the green chemistry method (AgGm), proving to be an innovative alternative in the management of DS.

Efficacy of photodynamic therapy in the treatment of oral candidiasis: a systematic review and meta-analysis

OBJECTIVE

To evaluate the clinical efficacy of photodynamic therapy (PDT) as an adjunct or alternative to traditional antifungal drugs in the treatment of oral candidiasis, and to provide evidence-based medical evidence for its use in the treatment of oral candidiasis.

METHODS

Computer combined with manual retrieval of China Academic Journals Full-text Database (CNKI), China Biomedical Literature Database (CBM), Chinese Science and Technology Journal Database (VIP), Wanfang Database, PubMed, Web of Science, Cochrane Library, Embase, Scopus retrieval for articles published before January 2023, basic information and required data were extracted according to the inclusion and exclusion criteria, and the Revman V5.4 software was used to conduct Meta-analysis of the included literature.

RESULTS

A total of 11 articles were included, 7 of which used nystatin as an antifungal drug, 2 of which were combined treatment of PDT and nystatin, 2 of the remaining 4 articles were treated with fluconazole, and 2 were treated with miconazole. Meta results showed that PDT was superior to nystatin in reducing the number of oral candida colonies in the palate of patients MD = -0.87, 95%CI = (-1.52,-0.23), P = 0.008, the difference was statistically significant, and the denture site MD = -1.03, 95%CI = (-2.21, -0.15), P = 0.09, the difference was not statistically significant; compared with the efficacy of fluconazole, RR = 1.01, 95%CI = (0.56,1.83), P = 0.96; compared with miconazole RR = 0.55, 95%CI = (0.38, 0.81), P = 0.002; PDT combined with nystatin RR = 1.27, 95%CI = (1.06, 1.52), P = 0.01; recurrence rate RR = 0.28, 95%CI = (0.09, 0.88), P = 0.03.

CONCLUSIONS

PDT was effective in the treatment of oral candidiasis; PDT was more effective than nystatin for the treatment of denture stomatitis in the palate, while there was no significant difference between the two for the denture site; The efficacy of PDT for oral candidiasis was similar to that of fluconazole; PDT was less effective than miconazole for oral candidiasis; Compared with nystatin alone, the combination of PDT and nystatin is more effective in treating oral candidiasis with less risk of recurrence.

Autophagy Alters the Susceptibility of Candida albicans Biofilms to Antifungal Agents

Candida albicans (C. albicans) reigns as a major cause of clinical candidiasis. C. albicans biofilms are known to increase resistance to antifungal agents, making biofilm-related infections particularly challenging to treat. Drug resistance is of particular concern due to the spread of multidrug-resistant fungal pathogens, while autophagy is crucial for the maintenance of cellular homeostasis. Therefore, this study aimed to investigate the effects of an activator and an inhibitor of autophagy on the susceptibility of C. albicans biofilms to antifungal agents and the related mechanisms. The susceptibility of C. albicans biofilms to different antifungal agents after treatment with or without the autophagy activator or inhibitor was evaluated using XTT assay. Alkaline phosphatase (ALP) activity and reactive oxygen species (ROS) level, as well as the expression of ROS-related and autophagy-related genes, were examined to evaluate the autophagic activity of C. albicans biofilms when treated with antifungal agents. The autophagosomes were observed by transmission electron microscopy (TEM). The susceptibility of C. albicans biofilms to antifungal agents changed when autophagy changed. The ALP activity and ROS level of C. albicans biofilms increased with the treatment of antifungal agents, and autophagosomes could be observed in C. albicans biofilms. Autophagy was involved in the susceptibility of C. albicans biofilms to antifungal agents.

Silver nanoparticles in denture adhesive: An antimicrobial approach against Candida albicans

OBJECTIVE

To evaluate the antimicrobial potential of silver nanoparticles (Ag NPs) synthesized using three different routes (ultraviolet light, Turkevich, and green chemistry method using Glycine max extract) associated with COREGA® denture powder adhesive.

METHODS

Heat-cured acrylic resin specimens were treated with different Ag NPs associated with the adhesive (AD + Ag UV, AD + Ag Turk, and AD + Ag Gm groups). As controls, the specimens were treated with a combination of adhesive and nystatin (AD + Nyst group), only adhesive (AD group), or submerged on the surface of the specimens (PBS group). After the treatments, biofilms of C. albicans developed for 3, 6, and 12 h on the specimen surfaces. The biofilm was quantified using colony-forming units per milliliter, colorimetric assay, and confocal laser scanning microscopy.

RESULTS

Regardless of the period, we observed an inhibition of fungal load and a reduction in metabolic activity and biofilm mass in the resin specimens treated with the combinations AD/Ag NPs, compared to AD and PBS. The antimicrobial action of the AD + Turk and AD + Ag Gm groups was similar than that for the AD + Nyst group in all periods and viability tests, except for the biofilm mass (12 h).

CONCLUSIONS

The COREGA® adhesive with Ag NPs, mainly those synthesized using the Turkevich and Glycine max methods, showed excellent antimicrobial activity against C. albicans biofilms, maintained for up to 12 h.

CLINICAL SIGNIFICANCE

The association of Ag NPs to the adhesive can add preventive or therapeutic effects against denture stomatitis, to this prosthetic material.

In vitro antifungal activity of lasiodiplodin, isolated from endophytic fungus Lasiodiplodia pseudotheobromae J-10 associated with Sarcandra glabra and optimization of culture conditions for lasiodiplodin production

A macrolide antibiotic, lasiodiplodin was isolated from the endophytic fungus (EF) Lasiodiplodia pseudotheobromae J-10 associated with the medicinal plant Sarcandra glabra. In vitro antifungal assay demonstrated the inhibitory activity of lasiodiplodin against the growth of six phytopathogenic fungi, with the IC₅₀ values ranging between 15.50 and 52.30 μg/mL. The highest antifungal activities were recorded against Exserohilum turcicum, Colletotrichum capsici, and Pestalotiopsis theae, with IC₅₀ values of 15.50, 15.90, and 17.55 μg/mL, respectively. The underlying mechanism of the antifungal activity of lasiodiplodin against E. turcicum included the alteration of its colony morphology and disturbance of its cell membrane integrity. In addition, the optimization of L. pseudotheobromae J-10 culture conditions increased lasiodiplodin yield to 52.33 mg/L from 0.59 mg/L at pre-optimization. This is the first report on the isolation and identification of antifungal compound from the EF L. pseudotheobromae J-10 associated with S. glabra, as well as on the optimization of L. pseudotheobromae J-10 culture conditions to increase lasiodiplodin yield. The results of this study support that lasiodiplodin is a natural compound with high potential bioactivity against phytopathogens, and provide a basis for further study of the EF associated with S. glabra.

Nystatin Effectiveness in Oral Candidiasis Treatment: A Systematic Review & Meta-Analysis of Clinical Trials

Oral candidiasis is the most common opportunistic fungal infection caused by commensal Candida species. Since there are various local and systemic predisposing factors for the disease, the treatment also varies from topical to systemic antifungal agents. Nystatin is a common antifungal agent used topically. The aim of this systematic review was to evaluate and compare the efficacy of different antifungal agents and the safety of nystatin in the treatment of oral candidiasis. Three electronic databases were searched for randomized controlled trials comparing nystatin with other anti-fungal therapies or placebo. Clinical and/or mycological cure was the outcome evaluation. A meta-analysis and descriptive study on the efficacy, treatment protocols, and safety of nystatin was also conducted. The meta-analysis included five studies, which compared the efficacy of nystatin suspensions with photodynamic therapy. A significant difference in the colony-forming units per milliliters (CFU/mL) of Candida species was observed at 60 days intervals for both palatal mucosa and denture surfaces, with both groups favoring nystatin with low heterogeneity at a 95% confidence interval. Nystatin and photodynamic therapy were found to be equally effective for the clinical remission of denture stomatitis as well as a significant reduction of CFU/mL of Candida species from dentures and palatal surfaces of the patients.

Antifungal activity of Punicalagin-nystatin combinations against Candida albicans

OBJECTIVES

Oral candidiasis is the most common opportunistic fungal infection of oral mucosa and results from an overgrowth of Candida, especially Candida albicans. The potential anti-C. albicans and cytotoxicity of punicalagin (PCG), isolated from Punica granatum, alone or with nystatin (NYS) were evaluated.

METHODS

Activity of compounds alone or in combinations was determined against two C. albicans strains (ATCC 90028 and SC5314). Minimal inhibitory concentration (MIC)-50 and Minimum Fungicidal Concentration (MFC) were assessed by XTT assay and CFU counts, respectively. For combinations, determination of fractional inhibitory concentration index was performed. Ergosterol pathway was investigated as a possible PCG antifungal mechanism. Cytotoxicity assays were undertaken on human primary oral keratinocytes and gingival fibroblasts incubated with antifungal concentrations of PCG and/or NYS for 24 hr.

RESULTS

Combination of NYS and PCG increased antifungal efficacy, compared with compounds tested alone. Combinations 4 (PCG-6.25 μg/ml; NYS-3.9 μg/ml) and 5 (PCG-12.5 μg/ml; NYS-1.95 μg/ml) were more effective since they reduced the MIC-50 of PCG (50 μg/ml) by 8 and 4 times, respectively, increased the candidal inhibition and nullified the PCG cytotoxicity for keratinocytes. PCG antifungal mechanism did not involve ergosterol biosynthesis pathway.

CONCLUSIONS

The favorable outcomes for combination of PCG and NYS encourage further testing this therapeutic strategy against C. albicans.

Efficacy of nystatin for the treatment of oral candidiasis: a systematic review and meta-analysis

Objective

To systematically review and assess the efficacy, different treatment protocols (formulation, dosage, and duration), and safety of nystatin for treating oral candidiasis.

Methods

Four electronic databases were searched for trials published in English till July 1, 2015. Randomized controlled trials comparing nystatin with other antifungal therapies or a placebo were included. Clinical and/or mycological cure was the outcome evaluation. A meta-analysis or descriptive study on the efficacy, treatment protocols, and safety of nystatin was conducted.

Results

The meta-analysis showed that nystatin pastille was significantly superior to placebo in treating denture stomatitis. Nystatin suspension was not superior to fluconazole in treating oral candidiasis in infants, children, or HIV/AIDS patients. The descriptive investigations showed that administration of nystatin suspension and pastilles in combination for 2 weeks might achieve a higher clinical and mycological cure rate, and using the nystatin pastilles alone might have a higher mycological cure rate, when compared with using nystatin suspensions alone. Nystatin pastilles at a dose of 400,000 IU resulted in a significantly higher mycological cure rate than that administrated at a dose of 200,000 IU. Furthermore, treatment with nystatin pastilles for 4 weeks seemed to have better clinical efficacy than treatment for 2 weeks. Descriptive safety assessment showed that poor taste and gastrointestinal adverse reaction are the most common adverse effects of nystatin.

Conclusion

Nystatin pastille was significantly superior to placebo in treating denture stomatitis, while nystatin suspension was not superior to fluconazole in treating oral candidiasis in infants, children, or HIV/AIDS patients. Indirect evidence from a descriptive study demonstrated that administration of nystatin pastille alone or pastille and suspension in combination is more effective than that of suspension alone; prolonged treatment duration for up to 4 weeks can increase the efficacy of nystatin. More well designed and high quality randomized control studies are needed to confirm these findings.